From 0c5c862749c05193cf4c513628328c6db02b5222 Mon Sep 17 00:00:00 2001 From: Martin Xu Date: Wed, 21 Jul 2010 23:07:35 -0700 Subject: [PATCH] Add initial support for DHCP client library --- gdhcp/client.c | 1229 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ gdhcp/common.c | 417 +++++++++++++++++++ gdhcp/common.h | 173 ++++++++ gdhcp/gdhcp.h | 100 +++++ 4 files changed, 1919 insertions(+) create mode 100644 gdhcp/client.c create mode 100644 gdhcp/common.c create mode 100644 gdhcp/common.h create mode 100644 gdhcp/gdhcp.h diff --git a/gdhcp/client.c b/gdhcp/client.c new file mode 100644 index 0000000..a6f0e8a --- /dev/null +++ b/gdhcp/client.c @@ -0,0 +1,1229 @@ +/* + * + * DHCP client library with GLib integration + * + * Copyright (C) 2009-2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include +#include + +#include + +#include "gdhcp.h" +#include "common.h" + +#define DISCOVER_TIMEOUT 3 +#define DISCOVER_RETRIES 3 + +#define REQUEST_TIMEOUT 3 +#define REQUEST_RETRIES 3 + +typedef enum _listen_mode { + L_NONE, + L2, + L3, +} ListenMode; + +typedef enum _dhcp_client_state { + INIT_SELECTING, + REQUESTING, + BOUND, + RENEWING, + REBINDING, + RELEASED, +} ClientState; + +struct _GDHCPClient { + gint ref_count; + GDHCPType type; + ClientState state; + int ifindex; + char *interface; + uint8_t mac_address[6]; + uint32_t xid; + uint32_t server_ip; + uint32_t requested_ip; + char *assigned_ip; + uint32_t lease_seconds; + ListenMode listen_mode; + int listener_sockfd; + uint8_t retry_times; + uint8_t ack_retry_times; + guint timeout; + guint listener_watch; + GIOChannel *listener_channel; + GList *require_list; + GList *request_list; + GHashTable *code_value_hash; + GHashTable *send_value_hash; + GDHCPClientEventFunc lease_available_cb; + gpointer lease_available_data; + GDHCPClientEventFunc no_lease_cb; + gpointer no_lease_data; + GDHCPClientEventFunc lease_lost_cb; + gpointer lease_lost_data; + GDHCPClientEventFunc address_conflict_cb; + gpointer address_conflict_data; + GDHCPDebugFunc debug_func; + gpointer debug_data; +}; + +static GTimer *timer = NULL; + +/* Initialize the packet with the proper defaults */ +static void init_packet(GDHCPClient *dhcp_client, + struct dhcp_packet *packet, char type) +{ + dhcp_init_header(packet, type); + + memcpy(packet->chaddr, dhcp_client->mac_address, 6); +} + +static void add_request_options(GDHCPClient *dhcp_client, + struct dhcp_packet *packet) +{ + int len = 0; + GList *list; + uint8_t code; + int end = dhcp_end_option(packet->options); + + for (list = dhcp_client->request_list; list; list = list->next) { + code = (uint8_t) GPOINTER_TO_INT(list->data); + + packet->options[end + OPT_DATA + len] = code; + len++; + } + + if (len) { + packet->options[end + OPT_CODE] = DHCP_PARAM_REQ; + packet->options[end + OPT_LEN] = len; + packet->options[end + OPT_DATA + len] = DHCP_END; + } +} + +static void add_binary_option(gpointer key, gpointer value, gpointer user_data) +{ + uint8_t *option = value; + struct dhcp_packet *packet = user_data; + + dhcp_add_binary_option(packet, option); +} + +static void add_send_options(GDHCPClient *dhcp_client, + struct dhcp_packet *packet) +{ + g_hash_table_foreach(dhcp_client->send_value_hash, + add_binary_option, packet); +} + +static int send_discover(GDHCPClient *dhcp_client, uint32_t requested) +{ + struct dhcp_packet packet; + + init_packet(dhcp_client, &packet, DHCPDISCOVER); + + packet.xid = dhcp_client->xid; + + if (requested) + dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); + + /* Explicitly saying that we want RFC-compliant packets helps + * some buggy DHCP servers to NOT send bigger packets */ + dhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576)); + + add_request_options(dhcp_client, &packet); + + add_send_options(dhcp_client, &packet); + + return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, + INADDR_BROADCAST, SERVER_PORT, + MAC_BCAST_ADDR, dhcp_client->ifindex); +} + +static int send_select(GDHCPClient *dhcp_client) +{ + struct dhcp_packet packet; + struct in_addr addr; + + init_packet(dhcp_client, &packet, DHCPREQUEST); + + packet.xid = dhcp_client->xid; + + dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, + dhcp_client->requested_ip); + dhcp_add_simple_option(&packet, DHCP_SERVER_ID, dhcp_client->server_ip); + + add_request_options(dhcp_client, &packet); + + add_send_options(dhcp_client, &packet); + + addr.s_addr = dhcp_client->requested_ip; + + return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, + INADDR_BROADCAST, SERVER_PORT, + MAC_BCAST_ADDR, dhcp_client->ifindex); +} + +static int send_renew(GDHCPClient *dhcp_client) +{ + struct dhcp_packet packet; + + init_packet(dhcp_client , &packet, DHCPREQUEST); + packet.xid = dhcp_client->xid; + packet.ciaddr = dhcp_client->requested_ip; + + add_request_options(dhcp_client, &packet); + + add_send_options(dhcp_client, &packet); + + return dhcp_send_kernel_packet(&packet, + dhcp_client->requested_ip, CLIENT_PORT, + dhcp_client->server_ip, SERVER_PORT); +} + +static int send_rebound(GDHCPClient *dhcp_client) +{ + struct dhcp_packet packet; + + init_packet(dhcp_client , &packet, DHCPREQUEST); + packet.xid = dhcp_client->xid; + packet.ciaddr = dhcp_client->requested_ip; + + add_request_options(dhcp_client, &packet); + + add_send_options(dhcp_client, &packet); + + return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, + INADDR_BROADCAST, SERVER_PORT, + MAC_BCAST_ADDR, dhcp_client->ifindex); +} + +static int send_release(GDHCPClient *dhcp_client, + uint32_t server, uint32_t ciaddr) +{ + struct dhcp_packet packet; + + init_packet(dhcp_client, &packet, DHCPRELEASE); + packet.xid = rand(); + packet.ciaddr = ciaddr; + + dhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); + + return dhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, + server, SERVER_PORT); +} + +static gboolean interface_is_up(int index) +{ + int sk, err; + struct ifreq ifr; + gboolean ret = FALSE; + + sk = socket(PF_INET, SOCK_DGRAM, 0); + if (sk < 0) { + perror("Open socket error"); + return FALSE; + } + + memset(&ifr, 0, sizeof(ifr)); + ifr.ifr_ifindex = index; + + err = ioctl(sk, SIOCGIFNAME, &ifr); + if (err < 0) { + perror("Get interface name error"); + goto done; + } + + err = ioctl(sk, SIOCGIFFLAGS, &ifr); + if (err < 0) { + perror("Get interface flags error"); + goto done; + } + + if (ifr.ifr_flags & IFF_UP) + ret = TRUE; + +done: + close(sk); + + return ret; +} + +static char *get_interface_name(int index) +{ + struct ifreq ifr; + int sk, err; + + if (index < 0) + return NULL; + + sk = socket(PF_INET, SOCK_DGRAM, 0); + if (sk < 0) { + perror("Open socket error"); + return NULL; + } + + memset(&ifr, 0, sizeof(ifr)); + ifr.ifr_ifindex = index; + + err = ioctl(sk, SIOCGIFNAME, &ifr); + if (err < 0) { + perror("Get interface name error"); + close(sk); + return NULL; + } + + close(sk); + + return g_strdup(ifr.ifr_name); +} + +static void get_interface_mac_address(int index, uint8_t *mac_address) +{ + struct ifreq ifr; + int sk, err; + + sk = socket(PF_INET, SOCK_DGRAM, 0); + if (sk < 0) { + perror("Open socket error"); + return; + } + + memset(&ifr, 0, sizeof(ifr)); + ifr.ifr_ifindex = index; + + err = ioctl(sk, SIOCGIFNAME, &ifr); + if (err < 0) { + perror("Get interface name error"); + goto done; + } + + err = ioctl(sk, SIOCGIFHWADDR, &ifr); + if (err < 0) { + perror("Get mac address error"); + goto done; + } + + memcpy(mac_address, ifr.ifr_hwaddr.sa_data, 6); + +done: + close(sk); +} + +static void remove_value(gpointer data, gpointer user_data) +{ + char *value = data; + g_free(value); +} + +static void remove_option_value(gpointer data) +{ + GList *option_value = data; + + g_list_foreach(option_value, remove_value, NULL); +} + +GDHCPClient *g_dhcp_client_new(GDHCPType type, + int ifindex, GDHCPClientError *error) +{ + GDHCPClient *dhcp_client; + + if (ifindex < 0) { + *error = G_DHCP_CLIENT_ERROR_INVALID_INDEX; + return NULL; + } + + dhcp_client = g_try_new0(GDHCPClient, 1); + if (dhcp_client == NULL) { + *error = G_DHCP_CLIENT_ERROR_NOMEM; + return NULL; + } + + dhcp_client->interface = get_interface_name(ifindex); + if (dhcp_client->interface == NULL) { + *error = G_DHCP_CLIENT_ERROR_INERFACE_UNAVAILABLE; + goto error; + } + + if (interface_is_up(ifindex) == FALSE) { + *error = G_DHCP_CLIENT_ERROR_INTERFACE_DOWN; + goto error; + } + + get_interface_mac_address(ifindex, dhcp_client->mac_address); + + dhcp_client->listener_sockfd = -1; + dhcp_client->listener_channel = NULL; + dhcp_client->listen_mode = L_NONE; + dhcp_client->ref_count = 1; + dhcp_client->type = type; + dhcp_client->ifindex = ifindex; + dhcp_client->lease_available_cb = NULL; + dhcp_client->no_lease_cb = NULL; + dhcp_client->lease_lost_cb = NULL; + dhcp_client->address_conflict_cb = NULL; + dhcp_client->listener_watch = 0; + dhcp_client->retry_times = 0; + dhcp_client->ack_retry_times = 0; + dhcp_client->code_value_hash = g_hash_table_new_full(g_direct_hash, + g_direct_equal, NULL, remove_option_value); + dhcp_client->send_value_hash = g_hash_table_new_full(g_direct_hash, + g_direct_equal, NULL, g_free); + dhcp_client->request_list = NULL; + dhcp_client->require_list = NULL; + + *error = G_DHCP_CLIENT_ERROR_NONE; + + return dhcp_client; + +error: + g_free(dhcp_client->interface); + g_free(dhcp_client); + return NULL; +} + +#define SERVER_AND_CLIENT_PORTS ((67 << 16) + 68) + +static int dhcp_l2_socket(int ifindex) +{ + int fd; + struct sockaddr_ll sock; + + /* + * Comment: + * + * I've selected not to see LL header, so BPF doesn't see it, too. + * The filter may also pass non-IP and non-ARP packets, but we do + * a more complete check when receiving the message in userspace. + * + * and filter shamelessly stolen from: + * + * http://www.flamewarmaster.de/software/dhcpclient/ + * + * There are a few other interesting ideas on that page (look under + * "Motivation"). Use of netlink events is most interesting. Think + * of various network servers listening for events and reconfiguring. + * That would obsolete sending HUP signals and/or make use of restarts. + * + * Copyright: 2006, 2007 Stefan Rompf . + * License: GPL v2. + * + * TODO: make conditional? + */ + static const struct sock_filter filter_instr[] = { + /* check for udp */ + BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9), + /* L5, L1, is UDP? */ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 2, 0), + /* ugly check for arp on ethernet-like and IPv4 */ + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2), /* L1: */ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x08000604, 3, 4),/* L3, L4 */ + /* skip IP header */ + BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* L5: */ + /* check udp source and destination ports */ + BPF_STMT(BPF_LD|BPF_W|BPF_IND, 0), + /* L3, L4 */ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, SERVER_AND_CLIENT_PORTS, 0, 1), + /* returns */ + BPF_STMT(BPF_RET|BPF_K, 0x0fffffff), /* L3: pass */ + BPF_STMT(BPF_RET|BPF_K, 0), /* L4: reject */ + }; + + static const struct sock_fprog filter_prog = { + .len = sizeof(filter_instr) / sizeof(filter_instr[0]), + /* casting const away: */ + .filter = (struct sock_filter *) filter_instr, + }; + + fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP)); + if (fd < 0) + return fd; + + if (SERVER_PORT == 67 && CLIENT_PORT == 68) + /* Use only if standard ports are in use */ + setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog, + sizeof(filter_prog)); + + sock.sll_family = AF_PACKET; + sock.sll_protocol = htons(ETH_P_IP); + sock.sll_ifindex = ifindex; + + if (bind(fd, (struct sockaddr *) &sock, sizeof(sock)) != 0) { + close(fd); + return -errno; + } + + return fd; +} + +static gboolean sanity_check(struct ip_udp_dhcp_packet *packet, int bytes) +{ + if (packet->ip.protocol != IPPROTO_UDP) + return FALSE; + + if (packet->ip.version != IPVERSION) + return FALSE; + + if (packet->ip.ihl != sizeof(packet->ip) >> 2) + return FALSE; + + if (packet->udp.dest != htons(CLIENT_PORT)) + return FALSE; + + if (ntohs(packet->udp.len) != (uint16_t)(bytes - sizeof(packet->ip))) + return FALSE; + + return TRUE; +} + +static int dhcp_recv_l2_packet(struct dhcp_packet *dhcp_pkt, int fd) +{ + int bytes; + struct ip_udp_dhcp_packet packet; + uint16_t check; + + memset(&packet, 0, sizeof(packet)); + + bytes = read(fd, &packet, sizeof(packet)); + if (bytes < 0) + return -1; + + if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) + return -1; + + if (bytes < ntohs(packet.ip.tot_len)) + /* packet is bigger than sizeof(packet), we did partial read */ + return -1; + + /* ignore any extra garbage bytes */ + bytes = ntohs(packet.ip.tot_len); + + if (sanity_check(&packet, bytes) == FALSE) + return -1; + + check = packet.ip.check; + packet.ip.check = 0; + if (check != dhcp_checksum(&packet.ip, sizeof(packet.ip))) + return -1; + + /* verify UDP checksum. IP header has to be modified for this */ + memset(&packet.ip, 0, offsetof(struct iphdr, protocol)); + /* ip.xx fields which are not memset: protocol, check, saddr, daddr */ + packet.ip.tot_len = packet.udp.len; /* yes, this is needed */ + check = packet.udp.check; + packet.udp.check = 0; + if (check && check != dhcp_checksum(&packet, bytes)) + return -1; + + memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) + + sizeof(packet.udp))); + + if (dhcp_pkt->cookie != htonl(DHCP_MAGIC)) + return -1; + + return bytes - (sizeof(packet.ip) + sizeof(packet.udp)); +} + +static gboolean check_package_owner(GDHCPClient *dhcp_client, + struct dhcp_packet *packet) +{ + if (packet->xid != dhcp_client->xid) + return FALSE; + + if (packet->hlen != 6) + return FALSE; + + if (memcmp(packet->chaddr, dhcp_client->mac_address, 6)) + return FALSE; + + return TRUE; +} + +static void start_request(GDHCPClient *dhcp_client); + +static gboolean request_timeout(gpointer user_data) +{ + GDHCPClient *dhcp_client = user_data; + + dhcp_client->retry_times++; + + start_request(dhcp_client); + + return FALSE; +} + +static gboolean listener_event(GIOChannel *channel, GIOCondition condition, + gpointer user_data); + +static int switch_listening_mode(GDHCPClient *dhcp_client, + ListenMode listen_mode) +{ + GIOChannel *listener_channel; + int listener_sockfd; + + if (dhcp_client->listen_mode == listen_mode) + return 0; + + if (dhcp_client->listen_mode != L_NONE) { + g_source_remove(dhcp_client->listener_watch); + dhcp_client->listener_channel = NULL; + dhcp_client->listen_mode = L_NONE; + dhcp_client->listener_sockfd = -1; + dhcp_client->listener_watch = 0; + } + + if (listen_mode == L_NONE) + return 0; + + if (listen_mode == L2) + listener_sockfd = dhcp_l2_socket(dhcp_client->ifindex); + else if (listen_mode == L3) + listener_sockfd = dhcp_l3_socket(CLIENT_PORT, + dhcp_client->interface); + else + return -EIO; + + if (listener_sockfd < 0) + return -EIO; + + listener_channel = g_io_channel_unix_new(listener_sockfd); + if (listener_channel == NULL) { + /* Failed to create listener channel */ + close(listener_sockfd); + return -EIO; + } + + dhcp_client->listen_mode = listen_mode; + dhcp_client->listener_sockfd = listener_sockfd; + dhcp_client->listener_channel = listener_channel; + + g_io_channel_set_close_on_unref(listener_channel, TRUE); + dhcp_client->listener_watch = + g_io_add_watch_full(listener_channel, + G_PRIORITY_HIGH, G_IO_IN, + listener_event, dhcp_client, + NULL); + g_io_channel_unref(dhcp_client->listener_channel); + + return 0; +} + +static void start_request(GDHCPClient *dhcp_client) +{ + if (dhcp_client->retry_times == REQUEST_RETRIES) { + dhcp_client->state = INIT_SELECTING; + + if (dhcp_client->no_lease_cb != NULL) + dhcp_client->no_lease_cb(dhcp_client, + dhcp_client->no_lease_data); + + return; + } + + if (dhcp_client->retry_times == 0) { + dhcp_client->state = REQUESTING; + switch_listening_mode(dhcp_client, L2); + } + + send_select(dhcp_client); + + dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH, + REQUEST_TIMEOUT, + request_timeout, + dhcp_client, + NULL); +} + +static uint32_t get_lease(struct dhcp_packet *packet) +{ + uint8_t *option_u8; + uint32_t lease_seconds; + + option_u8 = dhcp_get_option(packet, DHCP_LEASE_TIME); + if (option_u8 == NULL) + return 3600; + + lease_seconds = dhcp_get_unaligned((uint32_t *) option_u8); + lease_seconds = ntohl(lease_seconds); + /* paranoia: must not be prone to overflows */ + lease_seconds &= 0x0fffffff; + if (lease_seconds < 10) + lease_seconds = 10; + + return lease_seconds; +} + +static void restart_dhcp(GDHCPClient *dhcp_client, int retry_times) +{ + if (dhcp_client->timeout > 0) { + g_source_remove(dhcp_client->timeout); + dhcp_client->timeout = 0; + } + + dhcp_client->retry_times = retry_times; + dhcp_client->requested_ip = 0; + switch_listening_mode(dhcp_client, L2); + + g_dhcp_client_start(dhcp_client); +} + +static gboolean start_rebound_timeout(gpointer user_data) +{ + GDHCPClient *dhcp_client = user_data; + + switch_listening_mode(dhcp_client, L2); + + dhcp_client->lease_seconds >>= 1; + + /* We need to have enough time to receive ACK package*/ + if (dhcp_client->lease_seconds <= 6) { + + /* ip need to be cleared */ + if (dhcp_client->lease_lost_cb != NULL) + dhcp_client->lease_lost_cb(dhcp_client, + dhcp_client->lease_lost_data); + + restart_dhcp(dhcp_client, 0); + } else { + send_rebound(dhcp_client); + + dhcp_client->timeout = + g_timeout_add_seconds_full(G_PRIORITY_HIGH, + dhcp_client->lease_seconds >> 1, + start_rebound_timeout, + dhcp_client, + NULL); + } + + return FALSE; +} + +static void start_rebound(GDHCPClient *dhcp_client) +{ + dhcp_client->state = REBINDING; + + dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH, + dhcp_client->lease_seconds >> 1, + start_rebound_timeout, + dhcp_client, + NULL); +} + +static gboolean start_renew_timeout(gpointer user_data) +{ + GDHCPClient *dhcp_client = user_data; + gdouble elapse; + gulong microseconds; + + elapse = g_timer_elapsed(timer, µseconds); + + g_timer_start(timer); + + dhcp_client->state = RENEWING; + + dhcp_client->lease_seconds >>= 1; + + switch_listening_mode(dhcp_client, L3); + if (dhcp_client->lease_seconds <= 60) + start_rebound(dhcp_client); + else { + send_renew(dhcp_client); + + dhcp_client->timeout = + g_timeout_add_seconds_full(G_PRIORITY_HIGH, + dhcp_client->lease_seconds >> 1, + start_renew_timeout, + dhcp_client, + NULL); + } + + return FALSE; +} + +static void start_bound(GDHCPClient *dhcp_client) +{ + dhcp_client->state = BOUND; + + if (timer == NULL) + timer = g_timer_new(); + + dhcp_client->timeout = + g_timeout_add_seconds_full(G_PRIORITY_HIGH, + dhcp_client->lease_seconds >> 1, + start_renew_timeout, dhcp_client, + NULL); +} + +static gboolean restart_dhcp_timeout(gpointer user_data) +{ + GDHCPClient *dhcp_client = user_data; + + dhcp_client->ack_retry_times++; + + restart_dhcp(dhcp_client, dhcp_client->ack_retry_times); + + return FALSE; +} + +static char *get_ip(uint32_t ip) +{ + struct in_addr addr; + + addr.s_addr = ip; + + return g_strdup(inet_ntoa(addr)); +} + +/* get a rough idea of how long an option will be */ +static const uint8_t len_of_option_as_string[] = { + [OPTION_IP] = sizeof("255.255.255.255 "), + [OPTION_STRING] = 1, + [OPTION_U8] = sizeof("255 "), + [OPTION_U16] = sizeof("65535 "), + [OPTION_U32] = sizeof("4294967295 "), +}; + +static int sprint_nip(char *dest, const char *pre, const uint8_t *ip) +{ + return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]); +} + +/* Create "opt_value1 option_value2 ..." string */ +static char *malloc_option_value_string(uint8_t *option, GDHCPOptionType type) +{ + unsigned upper_length; + int len, optlen; + char *dest, *ret; + + len = option[OPT_LEN - OPT_DATA]; + type &= OPTION_TYPE_MASK; + optlen = dhcp_option_lengths[type]; + upper_length = len_of_option_as_string[type] * + ((unsigned)len / (unsigned)optlen); + dest = ret = malloc(upper_length + 1); + + while (len >= optlen) { + switch (type) { + case OPTION_IP: + dest += sprint_nip(dest, "", option); + break; + case OPTION_U16: { + uint16_t val_u16 = dhcp_get_unaligned( + (uint16_t *) option); + dest += sprintf(dest, "%u", ntohs(val_u16)); + break; + } + case OPTION_U32: { + uint32_t val_u32 = dhcp_get_unaligned( + (uint32_t *) option); + dest += sprintf(dest, type == OPTION_U32 ? "%lu" : + "%ld", (unsigned long) ntohl(val_u32)); + break; + } + case OPTION_STRING: + memcpy(dest, option, len); + dest[len] = '\0'; + return ret; + default: + break; + } + option += optlen; + len -= optlen; + if (len <= 0) + break; + *dest++ = ' '; + *dest = '\0'; + } + + return ret; +} + +static GList *get_option_value_list(char *value) +{ + char *pos = value; + GList *list = NULL; + + while ((pos = strchr(pos, ' ')) != NULL) { + *pos = '\0'; + + list = g_list_append(list, g_strdup(value)); + + value = ++pos; + } + + list = g_list_append(list, g_strdup(value)); + + return list; +} + +static void get_request(GDHCPClient *dhcp_client, struct dhcp_packet *packet) +{ + GDHCPOptionType type; + GList *list, *value_list; + char *option_value; + uint8_t *option; + uint8_t code; + + for (list = dhcp_client->request_list; list; list = list->next) { + code = (uint8_t) GPOINTER_TO_INT(list->data); + + option = dhcp_get_option(packet, code); + if (option == NULL) { + g_hash_table_remove(dhcp_client->code_value_hash, + GINT_TO_POINTER((int) code)); + continue; + } + + type = dhcp_get_code_type(code); + + option_value = malloc_option_value_string(option, type); + + value_list = get_option_value_list(option_value); + + g_free(option_value); + + if (value_list == NULL) + g_hash_table_remove(dhcp_client->code_value_hash, + GINT_TO_POINTER((int) code)); + else + g_hash_table_insert(dhcp_client->code_value_hash, + GINT_TO_POINTER((int) code), value_list); + } +} + +static gboolean listener_event(GIOChannel *channel, GIOCondition condition, + gpointer user_data) +{ + GDHCPClient *dhcp_client = user_data; + struct dhcp_packet packet; + uint8_t *message_type, *option_u8; + int re; + + if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) { + dhcp_client->listener_watch = 0; + return FALSE; + } + + if (dhcp_client->listen_mode == L_NONE) + return FALSE; + + if (dhcp_client->listen_mode == L2) + re = dhcp_recv_l2_packet(&packet, dhcp_client->listener_sockfd); + else if (dhcp_client->listen_mode == L3) + re = dhcp_recv_l3_packet(&packet, dhcp_client->listener_sockfd); + else + re = -EIO; + + if (re < 0) + return TRUE; + + if (check_package_owner(dhcp_client, &packet) == FALSE) + return TRUE; + + message_type = dhcp_get_option(&packet, DHCP_MESSAGE_TYPE); + if (message_type == NULL) + /* No message type option, ignore pakcage */ + return TRUE; + + switch (dhcp_client->state) { + case INIT_SELECTING: + if (*message_type != DHCPOFFER) + return TRUE; + + g_source_remove(dhcp_client->timeout); + dhcp_client->timeout = 0; + dhcp_client->retry_times = 0; + + option_u8 = dhcp_get_option(&packet, DHCP_SERVER_ID); + dhcp_client->server_ip = + dhcp_get_unaligned((uint32_t *) option_u8); + dhcp_client->requested_ip = packet.yiaddr; + + dhcp_client->state = REQUESTING; + + start_request(dhcp_client); + + return TRUE; + case REQUESTING: + case RENEWING: + case REBINDING: + if (*message_type == DHCPACK) { + dhcp_client->retry_times = 0; + + if (dhcp_client->timeout > 0) + g_source_remove(dhcp_client->timeout); + dhcp_client->timeout = 0; + + dhcp_client->lease_seconds = get_lease(&packet); + + get_request(dhcp_client, &packet); + + switch_listening_mode(dhcp_client, L_NONE); + + g_free(dhcp_client->assigned_ip); + dhcp_client->assigned_ip = get_ip(packet.yiaddr); + + /* Address should be set up here */ + if (dhcp_client->lease_available_cb != NULL) + dhcp_client->lease_available_cb(dhcp_client, + dhcp_client->lease_available_data); + + start_bound(dhcp_client); + } else if (*message_type == DHCPNAK) { + dhcp_client->retry_times = 0; + + if (dhcp_client->timeout > 0) + g_source_remove(dhcp_client->timeout); + + dhcp_client->timeout = g_timeout_add_seconds_full( + G_PRIORITY_HIGH, 3, + restart_dhcp_timeout, + dhcp_client, + NULL); + } + + break; + default: + break; + } + + return TRUE; +} + +static gboolean discover_timeout(gpointer user_data) +{ + GDHCPClient *dhcp_client = user_data; + + dhcp_client->retry_times++; + + g_dhcp_client_start(dhcp_client); + + return FALSE; +} + +int g_dhcp_client_start(GDHCPClient *dhcp_client) +{ + int re; + + if (dhcp_client->retry_times == DISCOVER_RETRIES) { + if (dhcp_client->no_lease_cb != NULL) + dhcp_client->no_lease_cb(dhcp_client, + dhcp_client->no_lease_data); + + return 0; + } + + if (dhcp_client->retry_times == 0) { + g_free(dhcp_client->assigned_ip); + dhcp_client->assigned_ip = NULL; + + dhcp_client->state = INIT_SELECTING; + re = switch_listening_mode(dhcp_client, L2); + if (re != 0) + return re; + + dhcp_client->xid = rand(); + } + + send_discover(dhcp_client, 0); + + dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH, + DISCOVER_TIMEOUT, + discover_timeout, + dhcp_client, + NULL); + return 0; +} + +void g_dhcp_client_stop(GDHCPClient *dhcp_client) +{ + switch_listening_mode(dhcp_client, L_NONE); + + if (dhcp_client->state == BOUND || + dhcp_client->state == RENEWING || + dhcp_client->state == REBINDING) + send_release(dhcp_client, dhcp_client->server_ip, + dhcp_client->requested_ip); + + if (dhcp_client->timeout > 0) { + g_source_remove(dhcp_client->timeout); + dhcp_client->timeout = 0; + } + + if (dhcp_client->listener_watch > 0) { + g_source_remove(dhcp_client->listener_watch); + dhcp_client->listener_watch = 0; + } + + dhcp_client->listener_channel = NULL; + + dhcp_client->retry_times = 0; + dhcp_client->ack_retry_times = 0; + + dhcp_client->requested_ip = 0; + dhcp_client->state = RELEASED; + dhcp_client->lease_seconds = 0; +} + +GList *g_dhcp_client_get_option(GDHCPClient *dhcp_client, + unsigned char option_code) +{ + return g_hash_table_lookup(dhcp_client->code_value_hash, + GINT_TO_POINTER((int) option_code)); +} + +void g_dhcp_client_register_event(GDHCPClient *dhcp_client, + GDHCPClientEvent event, + GDHCPClientEventFunc func, + gpointer data) +{ + switch (event) { + case G_DHCP_CLIENT_EVENT_LEASE_AVAILABLE: + dhcp_client->lease_available_cb = func; + dhcp_client->lease_available_data = data; + return; + case G_DHCP_CLIENT_EVENT_NO_LEASE: + dhcp_client->no_lease_cb = func; + dhcp_client->no_lease_data = data; + return; + case G_DHCP_CLIENT_EVENT_LEASE_LOST: + dhcp_client->lease_lost_cb = func; + dhcp_client->lease_lost_data = data; + return; + case G_DHCP_CLIENT_EVENT_ADDRESS_CONFLICT: + dhcp_client->address_conflict_cb = func; + dhcp_client->address_conflict_data = data; + return; + } +} + +int g_dhcp_client_get_index(GDHCPClient *dhcp_client) +{ + return dhcp_client->ifindex; +} + +char *g_dhcp_client_get_address(GDHCPClient *dhcp_client) +{ + return g_strdup(dhcp_client->assigned_ip); +} + +GDHCPClientError g_dhcp_client_set_request(GDHCPClient *dhcp_client, + unsigned char option_code) +{ + if (g_list_find(dhcp_client->request_list, + GINT_TO_POINTER((int) option_code)) == NULL) + dhcp_client->request_list = g_list_prepend( + dhcp_client->request_list, + (GINT_TO_POINTER((int) option_code))); + + return G_DHCP_CLIENT_ERROR_NONE; +} + +static uint8_t *alloc_dhcp_option(int code, const char *str, int extra) +{ + uint8_t *storage; + int len = strnlen(str, 255); + + storage = malloc(len + extra + OPT_DATA); + storage[OPT_CODE] = code; + storage[OPT_LEN] = len + extra; + memcpy(storage + extra + OPT_DATA, str, len); + + return storage; +} + +static const char *get_hostname(const char *host) +{ + char local_host_name[HOST_NAME_MAX + 1]; + + if (g_strcmp0("", host) != 0) + return g_strdup(host); + + if (gethostname(local_host_name, HOST_NAME_MAX) != 0) + return NULL; + + local_host_name[HOST_NAME_MAX] = 0; + + return g_strdup(local_host_name); +} + +/* Now only support send hostname */ +GDHCPClientError g_dhcp_client_set_send(GDHCPClient *dhcp_client, + unsigned char option_code, const char *option_value) +{ + uint8_t *binary_option; + const char *hostname; + + if (option_code == DHCP_HOST_NAME) { + hostname = get_hostname(option_value); + + binary_option = alloc_dhcp_option(option_code, hostname, 0); + + g_hash_table_insert(dhcp_client->send_value_hash, + GINT_TO_POINTER((int) option_code), binary_option); + } + + return G_DHCP_CLIENT_ERROR_NONE; +} + +void g_dhcp_client_ref(GDHCPClient *dhcp_client) +{ + g_atomic_int_inc(&dhcp_client->ref_count); +} + +void g_dhcp_client_unref(GDHCPClient *dhcp_client) +{ + if (g_atomic_int_dec_and_test(&dhcp_client->ref_count) == FALSE) + return; + + g_dhcp_client_stop(dhcp_client); + + g_free(dhcp_client->interface); + g_free(dhcp_client->assigned_ip); + + g_list_free(dhcp_client->request_list); + g_list_free(dhcp_client->require_list); + + g_hash_table_destroy(dhcp_client->code_value_hash); + g_hash_table_destroy(dhcp_client->send_value_hash); + + g_free(dhcp_client); +} + +void g_dhcp_client_set_debug(GDHCPClient *dhcp_client, + GDHCPDebugFunc func, gpointer data) +{ + dhcp_client->debug_func = func; + dhcp_client->debug_data = data; +} diff --git a/gdhcp/common.c b/gdhcp/common.c new file mode 100644 index 0000000..784844b --- /dev/null +++ b/gdhcp/common.c @@ -0,0 +1,417 @@ +/* + * DHCP library with GLib integration + * + * Copyright (C) 2007-2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include +#include +#include +#include +#include +#include +#include + +#include "gdhcp.h" +#include "common.h" + +static const DHCPOption client_options[] = { + { OPTION_IP, 0x01 }, /* subnet-mask */ + { OPTION_IP | OPTION_LIST, 0x03 }, /* routers */ + { OPTION_IP | OPTION_LIST, 0x06 }, /* domain-name-servers */ + { OPTION_STRING, 0x0f }, /* domain-name */ + { OPTION_IP | OPTION_LIST, 0x2a }, /* ntp-servers */ + { OPTION_U32, 0x33 }, /* dhcp-lease-time */ + /* Options below will not be exposed to user */ + { OPTION_IP, 0x32 }, /* requested-ip */ + { OPTION_U8, 0x35 }, /* message-type */ + { OPTION_U16, 0x39 }, /* max-size */ + { OPTION_STRING, 0x3c }, /* vendor */ + { OPTION_STRING, 0x3d }, /* client-id */ + { OPTION_UNKNOWN, 0x00 }, +}; + +GDHCPOptionType dhcp_get_code_type(uint8_t code) +{ + int i; + + for (i = 0; client_options[i].code; i++) { + if (client_options[i].code == code) + return client_options[i].type; + } + + return OPTION_UNKNOWN; +} + +uint8_t *dhcp_get_option(struct dhcp_packet *packet, int code) +{ + int len, rem; + uint8_t *optionptr; + uint8_t overload = 0; + + /* option bytes: [code][len][data1][data2]..[dataLEN] */ + optionptr = packet->options; + rem = sizeof(packet->options); + + while (1) { + if (rem <= 0) + /* Bad packet, malformed option field */ + return NULL; + + if (optionptr[OPT_CODE] == DHCP_PADDING) { + rem--; + optionptr++; + + continue; + } + + if (optionptr[OPT_CODE] == DHCP_END) { + if (overload & FILE_FIELD) { + overload &= ~FILE_FIELD; + + optionptr = packet->file; + rem = sizeof(packet->file); + + continue; + } else if (overload & SNAME_FIELD) { + overload &= ~SNAME_FIELD; + + optionptr = packet->sname; + rem = sizeof(packet->sname); + + continue; + } + + break; + } + + len = 2 + optionptr[OPT_LEN]; + + rem -= len; + if (rem < 0) + continue; /* complain and return NULL */ + + if (optionptr[OPT_CODE] == code) + return optionptr + OPT_DATA; + + if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) + overload |= optionptr[OPT_DATA]; + + optionptr += len; + } + + return NULL; +} + +int dhcp_end_option(uint8_t *optionptr) +{ + int i = 0; + + while (optionptr[i] != DHCP_END) { + if (optionptr[i] != DHCP_PADDING) + i += optionptr[i + OPT_LEN] + OPT_DATA - 1; + + i++; + } + + return i; +} + +/* + * Add an option (supplied in binary form) to the options. + * Option format: [code][len][data1][data2]..[dataLEN] + */ +void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) +{ + unsigned len; + uint8_t *optionptr = packet->options; + unsigned end = dhcp_end_option(optionptr); + + len = OPT_DATA + addopt[OPT_LEN]; + + /* end position + (option code/length + addopt length) + end option */ + if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) + /* option did not fit into the packet */ + return; + + memcpy(optionptr + end, addopt, len); + + optionptr[end + len] = DHCP_END; +} + +void dhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, + uint32_t data) +{ + uint8_t option[6], len; + GDHCPOptionType type = dhcp_get_code_type(code); + + if (type == OPTION_UNKNOWN) + return; + + option[OPT_CODE] = code; + + len = dhcp_option_lengths[type & OPTION_TYPE_MASK]; + option[OPT_LEN] = len; + +#if __BYTE_ORDER == __BIG_ENDIAN + data <<= 8 * (4 - len); +#endif + + dhcp_put_unaligned(data, (uint32_t *) &option[OPT_DATA]); + dhcp_add_binary_option(packet, option); + + return; +} + +void dhcp_init_header(struct dhcp_packet *packet, char type) +{ + memset(packet, 0, sizeof(*packet)); + + packet->op = BOOTREQUEST; + + switch (type) { + case DHCPOFFER: + case DHCPACK: + case DHCPNAK: + packet->op = BOOTREPLY; + } + + packet->htype = 1; + packet->hlen = 6; + packet->cookie = htonl(DHCP_MAGIC); + packet->options[0] = DHCP_END; + + dhcp_add_simple_option(packet, DHCP_MESSAGE_TYPE, type); +} + +static gboolean check_vendor(uint8_t *option_vendor, const char *vendor) +{ + uint8_t vendor_length = sizeof(vendor) - 1; + + if (option_vendor[OPT_LEN - OPT_DATA] != vendor_length) + return FALSE; + + if (memcmp(option_vendor, vendor, vendor_length) != 0) + return FALSE; + + return TRUE; +} + +static void check_broken_vendor(struct dhcp_packet *packet) +{ + uint8_t *vendor; + + if (packet->op != BOOTREQUEST) + return; + + vendor = dhcp_get_option(packet, DHCP_VENDOR); + if (vendor == NULL) + return; + + if (check_vendor(vendor, "MSFT 98") == TRUE) + packet->flags |= htons(BROADCAST_FLAG); +} + +int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd) +{ + int n; + + memset(packet, 0, sizeof(*packet)); + + n = read(fd, packet, sizeof(*packet)); + if (n < 0) + return -errno; + + if (packet->cookie != htonl(DHCP_MAGIC)) + return -EPROTO; + + check_broken_vendor(packet); + + return n; +} + +/* TODO: Use glib checksum */ +uint16_t dhcp_checksum(void *addr, int count) +{ + /* + * Compute Internet Checksum for "count" bytes + * beginning at location "addr". + */ + int32_t sum = 0; + uint16_t *source = (uint16_t *) addr; + + while (count > 1) { + /* This is the inner loop */ + sum += *source++; + count -= 2; + } + + /* Add left-over byte, if any */ + if (count > 0) { + /* Make sure that the left-over byte is added correctly both + * with little and big endian hosts */ + uint16_t tmp = 0; + *(uint8_t *) &tmp = *(uint8_t *) source; + sum += tmp; + } + /* Fold 32-bit sum to 16 bits */ + while (sum >> 16) + sum = (sum & 0xffff) + (sum >> 16); + + return ~sum; +} + +int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, + uint32_t source_ip, int source_port, uint32_t dest_ip, + int dest_port, const uint8_t *dest_arp, int ifindex) +{ + struct sockaddr_ll dest; + struct ip_udp_dhcp_packet packet; + int fd, n; + + enum { + IP_UPD_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - + EXTEND_FOR_BUGGY_SERVERS, + UPD_DHCP_SIZE = IP_UPD_DHCP_SIZE - + offsetof(struct ip_udp_dhcp_packet, udp), + }; + + fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP)); + if (fd < 0) + return -errno; + + memset(&dest, 0, sizeof(dest)); + memset(&packet, 0, sizeof(packet)); + packet.data = *dhcp_pkt; + + dest.sll_family = AF_PACKET; + dest.sll_protocol = htons(ETH_P_IP); + dest.sll_ifindex = ifindex; + dest.sll_halen = 6; + memcpy(dest.sll_addr, dest_arp, 6); + if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) { + close(fd); + return -errno; + } + + packet.ip.protocol = IPPROTO_UDP; + packet.ip.saddr = source_ip; + packet.ip.daddr = dest_ip; + packet.udp.source = htons(source_port); + packet.udp.dest = htons(dest_port); + /* size, excluding IP header: */ + packet.udp.len = htons(UPD_DHCP_SIZE); + /* for UDP checksumming, ip.len is set to UDP packet len */ + packet.ip.tot_len = packet.udp.len; + packet.udp.check = dhcp_checksum(&packet, IP_UPD_DHCP_SIZE); + /* but for sending, it is set to IP packet len */ + packet.ip.tot_len = htons(IP_UPD_DHCP_SIZE); + packet.ip.ihl = sizeof(packet.ip) >> 2; + packet.ip.version = IPVERSION; + packet.ip.ttl = IPDEFTTL; + packet.ip.check = dhcp_checksum(&packet.ip, sizeof(packet.ip)); + + /* + * Currently we send full-sized DHCP packets (zero padded). + * If you need to change this: last byte of the packet is + * packet.data.options[dhcp_end_option(packet.data.options)] + */ + n = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0, + (struct sockaddr *) &dest, sizeof(dest)); + if (n < 0) + return -errno; + + close(fd); + + return n; +} + +int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt, + uint32_t source_ip, int source_port, + uint32_t dest_ip, int dest_port) +{ + struct sockaddr_in client; + int fd, n, opt = 1; + + enum { + DHCP_SIZE = sizeof(struct dhcp_packet) - + EXTEND_FOR_BUGGY_SERVERS, + }; + + fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (fd < 0) + return -errno; + + setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); + + memset(&client, 0, sizeof(client)); + client.sin_family = AF_INET; + client.sin_port = htons(source_port); + client.sin_addr.s_addr = source_ip; + if (bind(fd, (struct sockaddr *) &client, sizeof(client)) < 0) { + close(fd); + return -errno; + } + + memset(&client, 0, sizeof(client)); + client.sin_family = AF_INET; + client.sin_port = htons(dest_port); + client.sin_addr.s_addr = dest_ip; + if (connect(fd, (struct sockaddr *) &client, sizeof(client)) < 0) { + close(fd); + return -errno; + } + + n = write(fd, dhcp_pkt, DHCP_SIZE); + + close(fd); + + if (n < 0) + return -errno; + + return n; +} + +int dhcp_l3_socket(int port, const char *interface) +{ + int fd, opt = 1; + struct sockaddr_in addr; + + fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); + + setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); + + if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, + interface, strlen(interface) + 1) < 0) { + close(fd); + return -1; + } + + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons(port); + if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) != 0) { + close(fd); + return -1; + } + + return fd; +} diff --git a/gdhcp/common.h b/gdhcp/common.h new file mode 100644 index 0000000..ade49cd --- /dev/null +++ b/gdhcp/common.h @@ -0,0 +1,173 @@ +/* + * + * DHCP client library with GLib integration + * + * Copyright (C) 2009-2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#include +#include + +#include + +#include "gdhcp.h" + +#define dhcp_get_unaligned(ptr) \ +({ \ + struct __attribute__((packed)) { \ + typeof(*(ptr)) __v; \ + } *__p = (void *) (ptr); \ + __p->__v; \ +}) + +#define dhcp_put_unaligned(val, ptr) \ +do { \ + struct __attribute__((packed)) { \ + typeof(*(ptr)) __v; \ + } *__p = (void *) (ptr); \ + __p->__v = (val); \ +} while (0) + +#define CLIENT_PORT 68 +#define SERVER_PORT 67 + +#define EXTEND_FOR_BUGGY_SERVERS 80 + +static const uint8_t MAC_BCAST_ADDR[6] __attribute__((aligned(2))) = { + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff +}; + +/* DHCP packet */ +#define DHCP_MAGIC 0x63825363 +#define DHCP_OPTIONS_BUFSIZE 308 +#define BOOTREQUEST 1 +#define BOOTREPLY 2 + +#define BROADCAST_FLAG 0x8000 + +/* See RFC 2131 */ +struct dhcp_packet { + uint8_t op; + uint8_t htype; + uint8_t hlen; + uint8_t hops; + uint32_t xid; + uint16_t secs; + uint16_t flags; + uint32_t ciaddr; + uint32_t yiaddr; + uint32_t siaddr_nip; + uint32_t gateway_nip; + uint8_t chaddr[16]; + uint8_t sname[64]; + uint8_t file[128]; + uint32_t cookie; + uint8_t options[DHCP_OPTIONS_BUFSIZE + EXTEND_FOR_BUGGY_SERVERS]; +} __attribute__((packed)); + +struct ip_udp_dhcp_packet { + struct iphdr ip; + struct udphdr udp; + struct dhcp_packet data; +} __attribute__((packed)); + +/* See RFC 2132 */ +#define DHCP_PADDING 0x00 +#define DHCP_SUBNET 0x01 +#define DHCP_ROUTER 0x03 +#define DHCP_TIME_SERVER 0x04 +#define DHCP_NAME_SERVER 0x05 +#define DHCP_DNS_SERVER 0x06 +#define DHCP_HOST_NAME 0x0c +#define DHCP_DOMAIN_NAME 0x0f +#define DHCP_NTP_SERVER 0x2a +#define DHCP_REQUESTED_IP 0x32 +#define DHCP_LEASE_TIME 0x33 +#define DHCP_OPTION_OVERLOAD 0x34 +#define DHCP_MESSAGE_TYPE 0x35 +#define DHCP_SERVER_ID 0x36 +#define DHCP_PARAM_REQ 0x37 +#define DHCP_ERR_MESSAGE 0x38 +#define DHCP_MAX_SIZE 0x39 +#define DHCP_VENDOR 0x3c +#define DHCP_CLIENT_ID 0x3d +#define DHCP_END 0xff + +#define OPT_CODE 0 +#define OPT_LEN 1 +#define OPT_DATA 2 +#define OPTION_FIELD 0 +#define FILE_FIELD 1 +#define SNAME_FIELD 2 + +/* DHCP_MESSAGE_TYPE values */ +#define DHCPDISCOVER 1 +#define DHCPOFFER 2 +#define DHCPREQUEST 3 +#define DHCPDECLINE 4 +#define DHCPACK 5 +#define DHCPNAK 6 +#define DHCPRELEASE 7 +#define DHCPINFORM 8 +#define DHCP_MINTYPE DHCPDISCOVER +#define DHCP_MAXTYPE DHCPINFORM + +typedef enum { + OPTION_UNKNOWN, + OPTION_IP, + OPTION_STRING, + OPTION_U8, + OPTION_U16, + OPTION_U32, + OPTION_TYPE_MASK = 0x0f, + OPTION_LIST = 0x10, +} GDHCPOptionType; + +typedef struct dhcp_option { + GDHCPOptionType type; + uint8_t code; +} DHCPOption; + +/* Length of the option types in binary form */ +static const uint8_t dhcp_option_lengths[] = { + [OPTION_IP] = 4, + [OPTION_STRING] = 1, + [OPTION_U8] = 1, + [OPTION_U16] = 2, + [OPTION_U32] = 4, +}; + +uint8_t *dhcp_get_option(struct dhcp_packet *packet, int code); +int dhcp_end_option(uint8_t *optionptr); +void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt); +void dhcp_add_simple_option(struct dhcp_packet *packet, + uint8_t code, uint32_t data); +GDHCPOptionType dhcp_get_code_type(uint8_t code); + +uint16_t dhcp_checksum(void *addr, int count); + +void dhcp_init_header(struct dhcp_packet *packet, char type); + +int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, + uint32_t source_ip, int source_port, + uint32_t dest_ip, int dest_port, + const uint8_t *dest_arp, int ifindex) ; +int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt, + uint32_t source_ip, int source_port, + uint32_t dest_ip, int dest_port) ; +int dhcp_l3_socket(int port, const char *interface); +int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd); diff --git a/gdhcp/gdhcp.h b/gdhcp/gdhcp.h new file mode 100644 index 0000000..f335f0b --- /dev/null +++ b/gdhcp/gdhcp.h @@ -0,0 +1,100 @@ +/* + * + * DHCP client library with GLib integration + * + * Copyright (C) 2009-2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#ifndef __G_DHCP_H +#define __G_DHCP_H + +#include + +#ifdef __cplusplus +extern "C" { +#endif + +struct _GDHCPClient; + +typedef struct _GDHCPClient GDHCPClient; + +typedef enum { + G_DHCP_CLIENT_ERROR_NONE, + G_DHCP_CLIENT_ERROR_INERFACE_UNAVAILABLE, + G_DHCP_CLIENT_ERROR_INTERFACE_IN_USE, + G_DHCP_CLIENT_ERROR_INTERFACE_DOWN, + G_DHCP_CLIENT_ERROR_NOMEM, + G_DHCP_CLIENT_ERROR_INVALID_INDEX, + G_DHCP_CLIENT_ERROR_INVALID_OPTION +} GDHCPClientError; + +typedef enum { + G_DHCP_CLIENT_EVENT_LEASE_AVAILABLE, + G_DHCP_CLIENT_EVENT_NO_LEASE, + G_DHCP_CLIENT_EVENT_LEASE_LOST, + G_DHCP_CLIENT_EVENT_ADDRESS_CONFLICT, +} GDHCPClientEvent; + +typedef enum { + G_DHCP_IPV4, + G_DHCP_IPV6, +} GDHCPType; + +#define G_DHCP_SUBNET 0x01 +#define G_DHCP_ROUTER 0x03 +#define G_DHCP_TIME_SERVER 0x04 +#define G_DHCP_DNS_SERVER 0x06 +#define G_DHCP_HOST_NAME 0x0c +#define G_DHCP_NTP_SERVER 0x2a + +typedef void (*GDHCPClientEventFunc) (GDHCPClient *client, gpointer user_data); + +typedef void (*GDHCPDebugFunc)(const char *str, gpointer user_data); + +GDHCPClient *g_dhcp_client_new(GDHCPType type, int index, + GDHCPClientError *error); + +int g_dhcp_client_start(GDHCPClient *client); +void g_dhcp_client_stop(GDHCPClient *client); + +void g_dhcp_client_ref(GDHCPClient *client); +void g_dhcp_client_unref(GDHCPClient *client); + +void g_dhcp_client_register_event(GDHCPClient *client, + GDHCPClientEvent event, + GDHCPClientEventFunc func, + gpointer user_data); + +GDHCPClientError g_dhcp_client_set_request(GDHCPClient *client, + unsigned char option_code); +GDHCPClientError g_dhcp_client_set_send(GDHCPClient *client, + unsigned char option_code, + const char *option_value); + +char *g_dhcp_client_get_address(GDHCPClient *client); +GList *g_dhcp_client_get_option(GDHCPClient *client, + unsigned char option_code); +int g_dhcp_client_get_index(GDHCPClient *client); + +void g_dhcp_client_set_debug(GDHCPClient *client, + GDHCPDebugFunc func, gpointer data); + +#ifdef __cplusplus +} +#endif + +#endif /* __G_DHCP_H */ -- 2.7.4